Commutator



Aug. 26 1924.

E. CLARKE COIIHUTA'I'OR Filed Nov; 23 1921 Q \NVENTOR BY I ATTORNEYPatented Aug. 26, 1924.

UNITED STATES ERNEST CLARKE, on ST. Louis, MISSOURI, WAGNER ELECTRICCORPORATION,

PATENT OFFICE.

COMIVIUTATOR.

Application filed November 23, 5223..

To all whom it may concern Be it known that I, ERNEST CLARKE, a citizenof the United States 01 America. residing at the city oi St. Louis,State oi Missouri, United States of America, have invented a certain newand useful Commutator, of which the following is such full, clear, andexact description, as will enable any one skilled in the art to which itappertains to make and use the same, refer ence being had to theaccompanying drawin s, forming part of this specification,

my invention relates to means for short circuiting a winding of analternating current motor on the occurrence of predetermined speed orother conditions and part-ioularly to means for mounting and positivelyretaining in desired position the conducting segments to which thewinding leads are connected. These segments are shaped and arranged asin the ordinary commutator and although in the particular embodiment ofthe invention herein described no brushes are employed, their use inother embodinients of the invention is contemplated and the assembleddevice will be herein referred to for convenience as a commutator.

One of the ditficulties in the manufacture of commutators arises fromthe necessity of having each segment firmly held and prop erly insulatedfrom adjacent segments and the fact that the heating of the segmentsincident to soldering the leads thereto produces strains and othereffects which often result in the loosening of segments. It is oneobject of my invention to provide improved segment supporting andclamping means which will result in a strong, rigid assembly of segmentsnot subject to impair-- ment by the operation of attaching the leads,Other objects are to produce a commutator assembly which can be easilymanufactured and at decreased cost of labor and material. One prior arttype of commutator assembly over which my invention is intended to be animprovement, is illustrated in Veichsel United States Patent No.1,214,980.

In the accompanying drawings, Figure 1 is a cross sectional view of aportion of a rotor of a polyphase motor having a commutator assemblyembodying my invention, the short circuiting device being in theposition which it occupies when the rotor is Serial No. 537, 91.

stationary; Figure 2 is view similar to Figure 1 but showing the shortcircuiting elements in running position; F i ure 3 is an end view o'l aportion oi? the commutator; and Figure 6' shows a portion oi the splitclamping ring for the commutator segments.

1 represents a rotor carrying laminations 2, a permanently shortcircuited winding and a winding of the commuted type Leads 5 from windin4: are connected to the commutator segments (3. T represents a steel cuphaving its outer edge flared outwardly in frusto-conical shape andprovided with an inner flange 9 through which the rotor shaft passes andby means of which the cup is supported on the shaft. Seated in the innerportion ot the cup is a cylindrical conducting ring 10. Split wedgingring 11 bears upon the frusto-conical portion of the cup and upon thecommutator segments through insulation between the ring and thesegments. The cooperating tapered surfaces of the cup and ring cause thering when pressed into position to firmly press the sides of the wedgeshaped commutator segments and the interposed insulation together andform a rigid cylindrical commutator. The lower surfaces of thecommutator segments and the inner surface of the conducting ring 10 arein alignment or substantially so when the wedging ring has been pressedinto position and the ring is held in position by turning over the outeredge of the cup 7. Exact alignment of inner surfaces of the commutatorand ring 10 is produced by malting a finishing cut on a lathe afterassembly.

The sleeve 12 slidable on the shaft 1 is actuated toward the positionshown in Figure 1 by the coil spring 13. A peripheral groove in thissleeve carries a plurality of short circuiting elements let looselymounted therein being loosely retained by a wire not shown which passesthrough holes in the ends of the members.

Upon occurrence of predetermined speed centrifugally operated means, notshown, but which may be of the type illustrated in the lVeichsel patentabove referred to, cause the rod 15 to move the sleeve 12 to the left tothe position shown in Figure 2 and centrifugal force acting upon theshort circuiting members 14 causes them to press firmly upon thesegments 6 and the conducting ring tion, said supporting member beingprovided. 10 thus short circuiting the winding 4 along with a flange toretain the wedging means in a plurality of axes.

The segments (3 are insulated from the ring 10 and from a wedge 11 asshown and preferably the cup 7 is covered with insulation, protecting itfrom electrical contact with the ends of the coils of the winding 4 andfrom the leads 5.

It will be apparent that the improved assembly of conducting segmentsherein shown in an application which constitutes it a multiple pointswitch, is applicable for use as the connnutator with which brushescooperate and in any type of machine requiring a commutator. I do not,therefore, intend that the scope of my invention be lim-- ited to theparticular application shown.

Having fully described my invention what I claim as new and desire tosecure by Letters fatent of the United States is:

l. In a device of the class dei ibed, the combination of an annularsupporting member having a tapered inner peripheral sun face, aplurality of segments circularly arranged therein, and means cooperatingwith the tapered surface of the annular member to hold the segn'ients inposition.

2. In a device of the class described, the combination of an annularsupporting member, a plurality of segments circularly arranged thcrein,and a split tapered wedging ring cooperating with the inner peripheralsurface of the annular member to clamp the segments by motion of thering longitudinally of the supporting member.

In a device of the class described, the combination of an annularsupporting member having a tapered inner peripheral surface, a pluralityof wedge-shaped conducting segments circularly arranged within thesupporting member, and a wedging ring cooperating with the taperedsurface of the supporting member to hold the segments in assembledrelation.

4. In a device of the class described, the combination of a supportingmember, a plurality of segments circularly arranged, wedging meanscooperating with the supporting member to hold the segments inposiwedging position.

5. In a device of the class described, the combination of a cup-shapedsupporting member, a plurality of wedge shaped con ducting segmentscircularly arranged within the supporting member, wedging means betweenthe inner peripheral surface of the supporting member and the segmentsto hold said segments in assembled relation, the outer edge of thesupporting member being bent inwardly to retain the wedging means.

6. In a device of the class described, the combination of a supportingmember having a frusto-conical interior surface, a plurality ofconducting segments circularly arranged within said supporting member,and wedging means cooperating with the frusto-conical surface and thesegn'ients to hold said segments in assembled relation.

7. In a device of the class described, the combination of a cup shapedsupporting member having a cylindrical portion and a frusto-conicalportion, a cylindrical conducting sleeve within the cylindrical portionof the cup, a plurality of conducting segments circularly arrangedwithin the frusto-conical portion of the cup, and wedging means betweensaid latter portion and the segments.

8. In a device of the class described the combination of a cup shapedsupporting member having a frusto-conical interior surface, a pluralityof conducting segments circularly arranged within the supporting memberwith outer surfaces parallel to the axis of the cup, a split wedgingring having its outer surface tapered to correspond with the taper ofthe frusto-conical surface of the cup, and insulating material betweenthe ring and the segments, the inner surface of the ring being parallelwith the axis of the cup and adapted to bear upon said insulatinmaterial to clamp the segments in assembled relation.

In testimony whereof, I have hereunto set my hand and allixed my seal.

ERNEST CLARKE. [L. 5.]

